Central heating boiler thermostat

swagman

My condensing (non-combi) oil boiler has 4 thermostat settings. The system also has a programmer, a room thermostat and there are TRVs on all but one radiator.

What is the optimum setting for the boiler thermostat in winter - is better efficiency/economy achieved by running it at maximum temperature setting?

latecomer

very difficult to say. Try looking in the manual and see if it gives any indication. Obviously a higher setting will use more gas but heat the house quicker and hence be on for less time.

economiser

Commercial boilers have an outside compensator to set the boiler temperature according to the outside temperature. With domestic system you can only do this manually. If you leave it on the highest setting it will work OK but with a condensing boiler you should run it as low as possible to get maximum efficiency. We adjust ours according to the weather, the colder the weather the higher the setting.

mikey72

If you run an oil fired boiler on the highest setting it is more prone to sooting up. Half to three quarters is probably better.